• Bulletin of the Korean Chemical Society
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• v.19 no.10
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• pp.1099-1105
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• 1998

A series of (diamine)isopropylidenmalonatoplatinum(Ⅱ) complexes and the oxidation products, (diamine)Pt (OOC)2C=C(CH3)2(X)2, (diamine=ethylenediamine(en), 1,2-diaminopropan(dap), N-methylethylenediamine(men); X=OH, OCOCH3, OCOCF3), have been prepared, and their interaction with guanosine-5'-monophosphate (5'-GMP) have been examined by means of 1H NMR spectroscopy. The present platinum(Ⅱ) complexes have shown to interact with 5'-GMP through N7 coordination in two concecutive steps in a similar way as with cisplatin, but no interaction between the present platinum(Ⅳ) complexes and 5'-GMP was observed. However, in the presence of ascorbic acid, the platinum(Ⅳ) complexes have been found to interact with 5'-GMP with the reaction rate depending on their reduction rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1724-1731
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• 2009

This study was aimed to investigate the effect of phyto-extract fermented mixture (MP119) on the male sexual functions. The MP119 was evaluated for anti-impotency and anti-hypertensive effects via ACE (angiotensin converting enzyme) or PDE (phosphodiesterase) inhibition assay. $IC_{50}$ values of MP119 against ACE and PDE were 241.3${\pm}$35.5 ppm and 372.2${\pm}$33.8 ppm, respectively. To investigate the effect of testosterone expression by MP119, we performed cell media test using mouse Leydig-derived TM3 cells. Production of testosterone in TM3 cell was increased by MP119. Also, NO (nitric oxide) production of HUVEC (human umbilical vein endothelial cell) was increased when MP119 was added to the cultures. Forty male ICR mice were divided into 4 groups. MP119 was orally intubated for 7 days to group 1 and 3, and same volume of vehicle to group 2 and 4 as controls. After that, group 3 and 4 were intraperitoneally injected cadmium chloride at a single dose of 2 mg/kg. On the 8th experimental day, weights of testis, epididymis and seminal vesicle, number of sperm, concentrations of serum testosterone and cGMP were determined. The number of sperm, the concentrations of testosterone and cGMP were significantly increased in two experimental groups (group 1, 3). These results suggest that MP119 enhanced the sexual function of male mice, and could protect the sexual organs from the cadmium chloride as one of the endocrine disrupters.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.797-801
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• 2005

While conducting an in vitro screening of various medicinal plant extracts, an aqueous extract of Rosa rugosa Radix (ARR) was found to exhibit a distinct vasorelaxant activity. ARR induced a concentration-dependent relaxation of the phenylephrine-precontracted aorta. This effect disappeared with the removal of functional endothelium. Pretreatment of the aortic tissues with NG-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]-oxadiazole-[4,3-]-quinoxalin-1-one (ODQ) completely inhibited the relaxation induced by ARR. ARR-induced vascular relaxations were also markedly attenuated by addition of diltiazem or verapamil. However, the relaxant effect of ARR was not blocked by pretreatment with indomethacine, tetraethylammonium (TEA), glibenclamide, atropine, or propranolol. Taken together, the present study suggests that ARR dilates vascular smooth muscle via endothelium-dependent NO/cGMP signaling.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.279-284
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• 1995

The aim of the present study was to know whether exogenously administered nitric oxide (NO) may differently modulate muscle mechanics between heart and aorta. We used PIANO method to generate NO. In isolated rat atrial tissues, neither heart rate nor contractility was affected by PIANO $(STZ,\;30{\sim}100\;{\mu}M)$. Only high concentration $(100\;{\mu}M)$ of 8-bromo cyclic GMP slightly depressed cardiac contractility. However, the same concentrations of 8-Br cGMP and PIANO significantly relaxed the rat thoracic aorta contracted with phenylephrine $(0.1\;{\mu}M)$. In isolated rabbit cardiac atrial myocytes, the amplitude of calcium currents were decreased in the whole voltage range by the presence of streptozotocin, which was further potentiated by UV light. Calcium currents were also decreased in those preparations treated with bradykinin, nitroprusside and 8-Br cGMP. These findings suggest that exogenous NO may modulate calcium current in cardiac myocyte. However, it remains why this does not affect myocardial contractility and heart rate. We concluded that NO may differently regulate calcium signal between aorta and heart muscle.

• Natural Product Sciences
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• v.23 no.3
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• pp.169-174
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• 2017

The aim of this study was to investigate the effect and action mechanism of quercetin on penile corpus cavernosum smooth muscle (PCCSM). PCCSM precontracted with phenylephrine (Phe) was treated with four different concentrations of quercetin ($10^{-7}$, $10^{-6}$, $10^{-5}$ and $10^{-4}M$). PCCSM were preincubated with N-Nitro-L-arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) to block nitric oxide synthase and guanylate cyclase, respectively. The changes in PCCSM tension were recorded, and cyclic nucleotides in the perfusate were measured by radioimmunoassay. The interactions of quercetin with phosphodiesterase type 5 inhibitors (PDE5-Is) such as sildenafil, udenafil and mirodenafil, were also evaluated. PCCSM relaxation induced by quercetin occurred in a concentrationdependent manner. The application of quercetin to PCCSM pre-treated with L-NAME and ODQ significantly inhibited the relaxation. Quercetin significantly increased cGMP in the perfusate. Furthermore, quercetin enhanced PDE5-Is-induced relaxation of PCCSM. Quercetin relaxed the PCCSM by activating the NO-cGMP signaling pathway, and it may be a therapeutic candidate or an alternative treatment for patients with erectile dysfunction who do not completely respond to PDE5-Is.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.5
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• pp.379-383
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• 2000

Pathophysiological implications of the vascular nitric oxide (NO)/cGMP pathway in hypertension were investigated. Sprague-Dawley rats were made deoxycorticosterone acetate (DOCA)-salt hypertensive for six weeks. The protein expression of endothelial constitutive NO synthase (ecNOS) and the tissue content of NO were determined in the thoracic aorta. The protein expression and catalytic activity of soluble guanylyl cyclase (GC) were also determined. Systolic blood pressure measured on the day of experiment was significantly higher in the experimental group than in the control. The hypertension was associated with decreases in the vascular tissue content of NO metabolites, concomitantly with the expression of ecNOS proteins. The protein expression of GC was not affected, while its catalytic activity was significantly decreased in hypertension. These results indicate that the high blood pressure is associated with a decreased activity of vascular NO/cGMP pathway in DOCA-salt hypertension.

• Journal of Chest Surgery
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• v.42 no.5
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• pp.576-587
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• 2009

Background: The up-regulation of the nitric oxide (NO)-cGMP pathway might be involved in the change of vascular reactivity in rats 3 days after they suffer acute myocardial infarction. However, the underlying mechanism for this has not been clarified. Material and Method: Acute myocardial infarction (AMI) was induced by occluding the left anterior descending coronary artery (LAD) for 30 min (Group AMI), whereas the sham-operated control rats were treated similarly without LAD occlusion (Group SHAM), The concentration-response relationships for phenylephrine (PE), KCl, acetylcholine (Ach) and sodium nitroprusside (SNP) were determined in the endothelium intact E(+) and endothelium denuded E(-) thoracic aortic rings from the rats 3 days after AMI or a SHAM operation. The concentration-response relationships of PE in the E(+) rings from the AMI rats were compared with those relationships in the rings pretreated with nitric oxide synthase (NOS) inhibitor $N{\omega}$-nitro-L-arginine methyl ester (L-NAME) or the cyclooxygenase inhibitor indomethacin. The plasma nitrite/nitrate concentrations were checked via a Griess reaction. The cyclic GMP content in the thoracic aortic rings was measured by radioimmunoassay and the endothelial nitric oxide synthase (eNOS) mRNA expression was assessed by real time PCR. Result: The mean infarct size (%) in the rats with AMI was $21.3{\pm}0.62%$. The heart rate and the systolic and diastolic blood pressure were not significantly changed in the AMI rats. The sensitivity of the contractile response to PE and KCl was significantly decreased in both the E(+) and E(-) aortic rings of the AMI group (p<0.05). L-NAME completely reversed these contractile responses whereas indomethacin did not (p<0.05). Moreover, the sensitivity of the relaxation response to Ach was also significantly decreased in the AMI group (p<0.05). The plasma nitrite and nitrate content (p<0.05), the basal cGMP content (p<0.05) and the eNOS mRNA expression (p=0.056) in the AMI rats were increased as compared with the SHAM group. Conclusion: Our findings indicate that the increased eNOS activity and the up-regulation of the NO-cGMP pathway can be attributed to the decreased contractile or relaxation response in the rat thoracic aorta 3 days after AMI.

• Journal of Yeungnam Medical Science
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• v.14 no.2
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• pp.337-349
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• 1997

This study was undertaken to examine the intensity of involvement of inducible nitric oxide synthase (iNOS) and cyclic GMP signal transduction pathway as one of the mechanisms of vaso-relaxative action of bacterial lipopolysaccharide (LPS) on the canine femoral artery strips. Canine femoral arteries were isolated and spiral strips of 10 mm long and 2 mm wide were made in the Tyrode solution of $0-4^{\circ}C$. The strips were prepared for isometric myography in Biancani's isolated muscle chamber containing 1 ml of Tyrode solution, which was maintained with pH 7.4 by aeration with 95% $O_2$/5% $CO_2$ at $37^{\circ}C$ and nitric oxide (NO) production was measured simulltaneously with isolated nitric oxide meter. LPS induced NO production, suppressed the phenylephrine (PE) induced contraction and enhanced the acetylcholine (ACh) induced relaxation. $N^G$-nitro-L-arginine methyl ester (L-NAME), an NOS inhibitor, methylene blue, a guanylyl cyclase inhibitor, potentiated PE induced contraction and suppressed ACh induced relaxation on the LPS treated strips. The inhibitory potency of methylene blue for LPS induced vascular hyporesponsiveness was stronger than that of L-NAME. These results suggest that in canine femoral artery, both iNOS and cyclic GMP signal trnasduction pathway are related with LPS induced vascular hyporeponsiveness, but in minor with iNOS and in major with cyclic GMP signal trnasduction pathway.

• Korean Journal of Pharmacognosy
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• v.37 no.2 s.145
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• pp.85-91
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• 2006

The present study was undertaken to evaluate the effect of evening primrose oil (EPO) on the male sexual functions. EPO (daily 0.5 ml/mouse) was orally intubated for 28 consecutive days to experimental ICR mice, and same vol. of vehicle to control mice. On the 14th and 28th experimental day, the testis weight, number of complete intromissions and mating, serum testosterone and cGMP levels, prostaglandin leveIs of penile corpus cavernosum smooth muscle cells, and NO-productive activity of endothelial cells were determined. The weight of body and testis, the number of complete intromissions during the 3hour period were somewhat increased in EPO treated mice than those of control. The number of sperm-positive females and testosterone level in serum were increased in experimental groups. The serum cGMP level was significantly increased but the NO production of ionomycin-stimulated HUVEC cells was not affected when EPO was added into cultures. These results suggest that oral administration of EPO enhanced the sexual functions of male mice, and EPO could be developed as a tonic improving sexual functions.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.337-341
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• 2006

The present study was designed to investigate the protein expression of nitric oxide synthase (NOS) and guanylyl cyclase (GC) activity in ischemia/perfusion (I/R) renal injury in rats. Renal I/R injury was experimentally induced by clamping the both renal pedicle for 40 min in Sprague-Dawley male rats. The renal expression of NOS isoforms was determined by Western blot analysis, and the activity of guanylyl cyclase was determined by the amount of guanosine 3', 5'-cyclic monophosphate (cGMP) formed in response to sodium nitroprusside (SNP), NO donor. I/R injury resulted in renal failure associated with decreased urine osmolality. The expression of inducible NOS (iNOS) was increased in I/R injury rats compared with controls, while endothelial NOS (eNOS) and neuronal NOS (nNOS) expression was decreased. The urinary excretion of NO metabolites was decreased in I/R injury rats. The cGMP production provoked by SNP was decreased in the papilla, but not in glomerulus. These results indicate an altered regulation of NOS expression and guanylyl cyclase activity in I/R-induced nephropathy.